The immune system safeguards our bodies against infections and cancers, but also causes autoimmuine diseases and rejection of transplanted organs. One of the fundamental properties of the immune system is the ability to regulate its own activities; this self-control prevents it from attacking healthy tissues and compels it to contract after successful elimination of the eliciting pathogens. Our research seeks to better understand the mechanisms of immunoregulation, with the hopes of applying it to the prevention of transplant rejection and diabetes.